But Dr Jarvis said if you really want it, and you burn the candle at both ends, anything is possible.
The 28-year-old is taking this weekend off work at Wellington Hospital, so that she can graduate from the University of Otago.
Her latest PhD was on "Innate-like T-cell function in patients with cancer".
She said recent scientific developments had developed immunotherapies that were widely used in the treatment of melanoma and blood cancers.
However, immunotherapies had not been effective in the treatment of prostate cancer — the sixth leading cause of cancer deaths among men worldwide.
In order to develop more effective immunotherapies, she studied the existing function of immune cells in men with prostate cancer.
"This identified impaired function of a group of immune cells called MAIT-cells.
"In the lab, MAIT-cells could be activated in combination with the immunotherapy pembrolizumab to kill prostate tumour cells."
She believed the research provided the foundation for development of MAIT-cell based immunotherapies for the treatment of prostate cancer.
Dr Jarvis said there were times when the work load became too much and she felt like chucking it all in, but her "amazing" husband Nathaniel Dasyam kept her going.
"He was there at the high points and the points when I thought I couldn’t get through it.
"He would just say, ‘we don’t have to do this tonight, but in a week or a month, I think you’ll regret giving up’.
"It was really a mindset that it was a marathon, not a sprint. And I was really well supported — that’s how I got through."
Eventually, she hopes to combine her medical degree with her PhD to become a medical oncologist.
She said she would have very mixed emotions when she walks across the graduation stage today.
"It will be quite emotional for me. All of this hard work, all the finality of it.
"It’s sort of sad to be over, glad to be over, looking forward to being able to use what I’ve learnt, use the connections that I’ve made, to make a difference in New Zealand in cancer treatment and research."
Now that her PhD was complete, Dr Jarvis said she would not have any trouble filling up all the new-found spare time she had.
"I’m now studying for my next medical exam which is in October next year.
"So unfortunately, I can’t get a dog yet. I won’t have time to take it for a walk."
Dr Jarvis will be one of 356 people graduating in person today at the 1pm ceremony, and 413 in absentia.
A further 363 people will graduate in person at the 4pm ceremony, and 107 in absentia.
